Process for reacting ketene with a vinyl ketone



Patented Dec. 9, 1941 PROCESS FOR REAC A VINYL halen-omthe-Rhine, I. G.

' Farbenindustrie TING KETENE KETONE Heinrich Hopfl and Wilhelm Bapp, Ludwigsy, asslgnors to Aktiengesellschaft,

Frankfort-on-the-Main, Germany No Drawing. Application March s, 1940, Serial No. 322,546. In Germany March 8; 1939 3Claims. ((1260-3445 The present invention relates to organic oxygen compounds and a process of producing same.

We have found that organic compounds containing oxygen which are suitable for a variety of applications and may easily be converted into When 'y-acylbutyric acids are to be prepared, it I is advantageous to remove any unconverted ketone after its reaction with the ketene and to -y-acylbutyric,acid substances may be obtained by causingketene to react with vinyl ketones. Suitable vinyl ketones are those containing besides the vinyl group an alkyl group, for example the methyl group, or a cycloalkyl, aralkyl or aryl group attached to the keto group. By the reaction are apparently formed the lactones oi the enolized -acylbutyric acids. These lactones maybe converted into wacylbutyric acid sub-' stances by means. of compounds containing at least one reactive hydrogen atom, especially water, alcohols, ammonia and primary or secondary amines. By a simple treatment with water or, if desired, with aqueous alkalies or acids, the lactones are converted into 'y-acylbutyric acids; by treating them with amideiorming agents, for example ammonia or primary or secondary amines, the corresponding amides are formed, while alcohols yield esters or the 'y-acylbutyric acids. r

The reaction proceeds according to the following scheme:

n-i z-cn=crn ketones it is usually advantageous to work in the absence of water, if desired, in the presence 0! inert solvents. Usually heating at a moderate temperature, say from 60 to 80 C., is advisable.

treat the reaction product formed with water. When the ketene is reacted with the vinyl ketone in the presence of water, y-acylbutyric acids are directly formed. The acids so obtained may be purified in any appropriate manner, for example by distillation.

The following example serves to illustrate how the present invention maybe carried out in practice but the invention is not restricted to this example.

Example Into a container filled to about half its content with vinyl-methyl ketone and provided with a reflux condenser ketene is introduced at about '70 to '75 C., while stirring, until the absorption subsides, whereupon the excess vinylmethyl ketone is distilled ofl'.

The residue is distilled in vacuo after some water has been added. -y-Acetylbutyric acidis thus obtained; it yields a crystallized semicarbazone in the form 01' leaflets which when recrystallized from methanol melts at between 'to C.

compounds containing oxygen which comprises causing ketene to react with methyl vinyl ketone.

HEINRICH HOEFF. WILHELM RAPP. 

